Ignore mock patch args when resolving step fixtures

Author: lin-hongkuan

CHANGES.rst

@@ -58,6 +58,7 @@ Fixed
 * Made type annotations stronger and removed most of the ``typing.Any`` usages and ``# type: ignore`` annotations. `#658 <https://github.com/pytest-dev/pytest-bdd/pull/658>`_
 * Empty docstrings are now correctly forwarded to step functions as an empty string instead of being silently dropped, which previously caused pytest to report a missing ``docstring`` fixture. `#809 <https://github.com/pytest-dev/pytest-bdd/issues/809>`_
 * Injecting a ``target_fixture`` no longer emits ``PytestRemovedIn10Warning`` on pytest 9.1+, which deprecated passing ``nodeid`` to ``_register_fixture``. `#823 <https://github.com/pytest-dev/pytest-bdd/issues/823>`_
+* Ignore ``unittest.mock.patch``-provided arguments when resolving step fixtures. `#330 <https://github.com/pytest-dev/pytest-bdd/issues/330>`_
 
 Security
 ++++++++

src/pytest_bdd/utils.py

@@ -11,6 +11,8 @@
 from typing import TYPE_CHECKING, TypeVar, cast, overload
 from weakref import WeakKeyDictionary
 
+from _pytest.compat import num_mock_patch_args
+
 if TYPE_CHECKING:
     from _pytest.config import Config
     from _pytest.pytester import RunResult
@@ -30,9 +32,10 @@ def get_required_args(func: Callable[..., object]) -> list[str]:
     :return: A list of argument names.
     """
     params = signature(func).parameters.values()
-    return [
+    required_args = [
         param.name for param in params if param.kind == param.POSITIONAL_OR_KEYWORD and param.default is param.empty
     ]
+    return required_args[num_mock_patch_args(func) :]
 
 
 def get_caller_module_locals(stacklevel: int = 1) -> dict[str, object]:

tests/steps/test_common.py

@@ -123,6 +123,40 @@ def _(foo, expected_value):
     assert foo2 == "test bar"
 
 
+def test_step_function_accepts_unittest_mock_patch_argument(pytester):
+    pytester.makefile(
+        ".feature",
+        mock_patch=textwrap.dedent(
+            """\
+            Feature: Mock patch arguments
+                Scenario: A step uses unittest.mock.patch as a decorator
+                    Then the patched function is called
+            """
+        ),
+    )
+    pytester.makepyfile(
+        textwrap.dedent(
+            """\
+        from pathlib import Path
+        from unittest.mock import patch
+
+        from pytest_bdd import scenarios, then
+
+        scenarios("mock_patch.feature")
+
+
+        @then("the patched function is called")
+        @patch("pathlib.Path.cwd")
+        def _(cwd_mock):
+            Path.cwd()
+            cwd_mock.assert_called_once_with()
+        """
+        )
+    )
+    result = pytester.runpytest()
+    result.assert_outcomes(passed=1)
+
+
 def test_step_functions_same_parser(pytester):
     pytester.makefile(
         ".feature",